Seminiferous tubules, rete testis and efferent ductules in ERKO and wild-type mice. a, Wild-type seminiferous tubules exhibit normal spermatogenesis and a small rete testis (RT). b, ERKO rete testis and seminiferous tubules (ST) are dilated. Spermatogenesis appears abnormal in several tubules. c, Wild-type efferent ductules (DE) have narrow lumen. d, ERKO efferent ductules have dilated lumen. e, Wild-type efferent-ductule epithelium contains endocytotic vesicles (EV) and numerous PAS+ lysosomes (L). f, ERKO efferent-ductule epithelium is reduced in height and non-ciliated cells (N) contain fewer lysosomes and endocytotic vesicles; C, cilia. Scale bars: a, b, 100 μm; c, d, 50μm; e, f, 10μm.